
bool judeg = false;
void setup() {
  // put your setup code here, to run once:
  pinMode(7, OUTPUT);
  pinMode(2, INPUT_PULLUP);
}

void loop() {
  // put your main code here, to run repeatedly:
  while (digitalRead(2) == HIGH) {}
  if (judeg) {
    digitalWrite(7, HIGH);
  } else {
    digitalWrite(7, LOW);
  }
  judeg = !judeg;
  delay(500);
}
